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Arachnids

Please choose an order from the list below:

Scorpions	False Scorpions	Harvester Spiders
Whip Scorpions	Whip Spiders	Short-tailed Whip Scorpions
Mini Whip Scorpions	Sun Spiders	Hooded Tickspiders
Mites and Ticks	Spiders

Class Arachnida

Arachnida is a large and well-known class of 8-legged arthropods related to crustaceans and insects. Unlike insects, the body is separated into only 2 parts. The cephalothorax, also known as the prosoma, contains the mouth area as well as the chelicerae (pincers or claws used for feeding), pedipalpi (feet used to touch or capture) and 8 legs, four on either side. Arachnids lack antannae. The cephalothorax is partially or completely covered with a protective shield. The second segment is known as the abdomen or opisthosoma, and contains the rest of the body. The abdomen may lack appendages entirely, or it may have specialized appendages, such as the spinneret used to make spiderwebs. Most arachnids breath in through tracheae or book lungs.

Most arachnid species are considered to be pests or are thought to be dangerous to humans.some spiders can kill humans, but these occurrences are very rare. Scorpions are also poisonous, and ticks can spread deadly illnesses, such as lyme disease. Arachnids are found throughout the world, from ponds to rainforests to desert to attics. They prefer warmer climates.

There are approx 60 000 species, with many more waiting to be discovered. There are 11 orders with living members today:

Scorpiones (scorpions) 1200 spp
Pseudoscorpiones or Chelonethida (false scorpions) 2000 spp
Opiliones or Phalangida (harvester spiders) 5000 spp
Uropygi (whip scorpions) 100 spp
Amblypygi (whip spiders or tailless whip scorpions) 70 spp
Schizomida (shortailed whip scorpions)
Palpigradi (miniature whip scorpions) 60 spp
Solifugae or Solpugida (sun spiders) 900 spp
Ricinulei (hooded tickspiders)
Acari (mites, ticks) 25 000 spp
Araneae (spiders) 35 000 spp

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